Semiconductor device having a catalyst enhanced crystallized layer

1. A thin-film transitor comprising: a non-single crystalline semiconductor film comprising silicon and containing a catalyst material which is capable of promoting crystallization of silicon, said semiconductor film having crystallinity; a gate insulating film adjacent to said semiconductor film; and a gate electrode adjacent to said insulating film; wherein concentration of said material does not exceed 1.times.10.sup.19 atom/cm.sup.3.

2. The transistor of claim 1 wherein said concentration of said material is 1.times.10.sup.15 atoms/cm.sup.3 or more.

3. The transistor of claim 1 wherein said semiconductor film contains 1.times.10.sup.15 atoms/cm.sup.3 to 5 atomic % of hydrogen.

4. A thin-film transistor comprising: a polycrystalline semiconductor film comprising silicon and containing a catalyst material which is capable of promoting crystallization of silicon; a gate insulating film adjacent to said semiconductor film; and a gate electrode adjacent to said insulating film; wherein concentration of said material does not exceed 1.times.10.sup.19 atom/cm.sup.3.

5. The transistor of claim 4 wherein said concentration of said material is 1.times.10.sup.15 atoms/cm.sup.3 or more.

6. The transistor of claim 4 wherein said semiconductor film contains 1.times.10.sup.15 atoms/cm.sup.3 to 5 atomic % hydrogen.

7. A semiconductor comprising: a crystalline semiconductor film comprising silicon and doped with hydrogen at a concentration not higher than 5 atomic %; wherein said semiconductor film contains a catalyst which is capable of promoting an amorphous silicon and a concentration of said catalyst in said crystalline semiconductor film does not exceed 1.times.10.sup.19 atoms/cm.sup.3.

8. The semiconductor of claim 7 wherein said concentration of said catalyst is 1.times.10.sup.15 atoms/cm.sup.3 or more.

9. The semiconductor of claim 7 wherein the concentration of said hydrogen is higher than 1.times.10.sup.15 atoms/cm.sup.3.

10. The semiconductor of claim 7 wherein the semiconductor contains 1.times.10.sup.19 atoms/cm.sup.3 or less each of carbon, oxygen, and nitrogen.

11. The semiconductor of claim 7 wherein the crystallization of the silicon film is confirmed by raman scattering spectroscopy.

12. The semiconductor of claim 7 wherein the semiconductor is formed on an insulating surface.

13. A thin-film transistor comprising: a non-single crystalline semiconductor film comprising silicon formed on an insulating surface, said semiconductor film having a crystallinity and being doped with a catalyst metal; a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween, wherein said metal is introduced into said semiconductor film for crystallization thereof and removed such that concentration of said material does not exceed 1.times.10.sup.19 atoms/cm.sup.3.

14. The transistor of the claim 13 wherein the removal of said metal is performed by annealing said semiconductor film in an atmosphere containing chlorine atoms.

15. The transistor of the claim 13 wherein the removal of said metal is performed by dissolving a metal silicide in hydrofluoric acid or hydrochloric acid, said metal silicide being formed by said introducing.

16. A thin-film transistor comprising: a crystalline semiconductor film comprising silicon and containing a catalyst metal which is capable of promoting crystallization of silicon at a concentration not higher than 1.times.10.sup.19 atom/cm.sup.3 ; a gate insulating film adjacent to said semiconductor film; and a gate electrode adjacent to said insulating film; wherein said crystalline semiconductor film is formed by a method comprising the steps of: depositing an amorphous semiconductor film comprising silicon on an insulating surface; providing said amorphous semiconductor film with a material containing said catalyst metal; then crystallizing said amorphous semiconductor film; and reducing the concentration of said catalyst metal by treating a surface of the crystallized semiconductor film with a gettering agent including fluorine or chlorine.

17. The transistor of the claim 16 wherein said gettering agent is a gas containing a chloride.

18. The transistor of the claim 16 wherein said gettering agent is a hydrofluoric acid or hydrochloric acid.

19. The transistor of the claim 16 wherein said gettering agent is a gas containing a chloride.

20. The transistor of the claim 16 wherein said gettering agent is a hydrofluoric acid or hydrochloric acid.

21. A thin-film transistor comprising: a crystalline semiconductor film comprising silicon and containing a catalyst metal which is capable of promoting crystallization of silicon at a concentration not higher than 1.times.10.sup.19 atom/cm.sup.3 ; a gate insulating film adjacent to said semiconductor film; and a gate electrode adjacent to said insulating film; wherein said crystalline semiconductor film is formed by a method comprising the steps of: depositing an amorphous semiconductor film comprising silicon on an insulating surface; providing a selected portion of said amorphous semiconductor film with a material containing said catalyst metal; heating said amorphous semiconductor film so that said amorphous semiconductor film is crystallized horizontally with respect to said insulating surface; and reducing the concentration of said catalyst metal by treating a surface of the crystallized semiconductor film with a gettering agent including fluorine or chlorine.

22. A transistor according to claim 21 wherein said crystalline semiconductor film includes hydrogen.

23. A semiconductor device comprising a crystalline semiconductor film including hydrogen, said crystalline semiconductor film comprising silicon and containing a catalyst material at a concentration not higher than 1.times.10.sup.19 atoms/cm.sup.3, wherein said catalyst material is capable of promoting crystallization of said semiconductor film.

24. A semiconductor device according to claim 23 wherein said semiconductor device is an N-channel type and a field effect mobility of said crystalline semiconductor film is 150 to 200 cm.sup.2 /Vs.

25. A semiconductor device according to claim 23 wherein said catalyst material comprises a metal selected from the group consisting of nickel, iron, cobalt, platinum, and palladium.

26. A semiconductor device comprising a crystalline semiconductor film including hydrogen, said crystalline semiconductor film comprising silicon and containing a catalyst material at a concentration not higher than 1.times.10.sup.19 atoms/cm.sup.3, wherein said catalyst material is capable of promoting crystallization of said semiconductor film and wherein said semiconductor device is an N-channel type and said crystalline semiconductor film has a field effect mobility of 40 to 60 cm.sup.2 /Vs.

27. A semiconductor device comprising a crystalline semiconductor film including hydrogen, said crystalline semiconductor film comprising silicon and containing a catalyst material at a concentration not higher than 1.times.10.sup.19 atoms/cm.sup.3, wherein said catalyst material is capable of promoting crystallization of said semiconductor film and wherein said semiconductor device is an N-channel type and said crystalline semiconductor film has a field effect mobility of 30 to 50 cm.sup.2 /Vs.